Beta testI have gone through the source code and refreshed most of it, it has been prepared for Lion.

However for those with issues with ACPI read due to older incompatible versions of their ACPI BIOS, will not benefit from this update. An update addressing this issue would need a custom ACPI read module, and I have no immediate plans for the moment.

What does this thing do and where to get it?Interface between ACPI control method batteries and OS X powermanagement controls. Basically get the battery icon. Downloads -> Release Editions, Debug Editions and Source.

Doesn't work?There is an option in the Info.plist called Quirck and enable it if you have a bad ACPI. It might work better for you.You can post bug report at the bug forum. If it is worth reporting do it properly.Some have reported that OS X misbehaves when on battery and system-id is not 2 (i.e. laptop).

System Requirements?

ACPI Control Method Battery

Original OS X PowerManagement.bundle for 10.6.x (no hacks or tweaks must be applied)